Dark Cosmos Collection

The darkest, richest textured and coloured cosmos together in one pack. Enjoy picking hundreds of vases of them from late June until at least October. More
140 seeds 030110 £4.95 In stock
Items will be despatched in 5-7 working days.
10 seedlings 510331-10 £11.50 Delivery early March
When in stock, please allow up to 2 weeks for delivery.
20 seedlings 510331-20 £18.50 Delivery early March
When in stock, please allow up to 2 weeks for delivery.
More Details

The darkest, richest textured and coloured cosmos together in one pack. Enjoy picking hundreds of vasefuls from late June until at least October.

Cosmos are stacked full with nectar and pollen – bees and butterflies love them. They are also very easy to grow, so are perfect for beginners.

The seed packet contains a mix of both varieties whilst the seedling Collection includes 5 or 10 seedlings each of:
Genus Cosmos
Type Half-Hardy Annual
Border Position Middle
Soil Type Chalky, Neutral
Scent Unscented
Site Full Sun
Moisture Moist but Well-drained, Well-drained
Height 1.2m (3ft 11in)
Spacing 45cm (18in) apart, 15 seedlings fills 5m² (ie 5m x 1m border, or 2.5m x 2m patch)
Sowing, Seeds, Planting Sow under cover in mid spring and plant out after last frosts, or direct sow early May. Clear area, dig over, rake soil to form a fine seed bed into which seeds will readily germinate. Scatter seeds evenly, rake over and water.
Care Tips Pinch out to promote bushier plants, deadhead regularly. May need some support.
Flowering July - October
Vase Life 7-10 days, no conditioning needed. This is a cut-and-come-again variety.
Harvesting Flower production: 4-5 months.
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
  • Sow Under Cover/Plant Indoors
  • Direct Sow/Plant Outdoors
  • Flowers/Harvest
Advice & Videos
How to plant and grow cosmos

Even if you only have a tiny garden – or just some pots – you have to grow at least one cosmos. They are the lowest maintenance,...

Direct sowing seeds

Learn how to get great results when direct sowing hardy annual seeds.


Plant Delivery - When in stock, please allow up to 2 weeks for delivery.

Seeds Delivery - Items will be despatched in 5-7 working days.

Click here to find out more information about our delivery rates and times.

Dark Cosmos Collection reviews

* * * * - Average based on 32 reviews

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Reviewed 22nd November 2018 by Yvonne

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Reviewed 16th November 2018 by Timothy

Lovely colours. Very sturdy plants that grew higher than expected (nearly 6 feet) and are still blooming in November in this unusual year

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Reviewed 14th November 2018 by Melissa

Cosmos still going strong in mid November

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Reviewed 10th November 2018 by Sally

Great plants, service and information.

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Reviewed 9th November 2018 by Judith

Didn't perform quite as well as your white cosmos I grew from seed.

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Reviewed 7th November 2018 by Karen

I was thrilled with my cosmos this year; they're still flowering in November, and have provided me with constant, really lovely flowers. Shall definitely get them again next year.

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Reviewed 7th November 2018 by Jenny

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Reviewed 7th November 2018 by Marion

Many of these were pink and taller so very disappointing as they looked so wrong with the red. I didn’t bother to complain as I’d had problems with the dahlia colours- again wrong colours supplied and also with the solar lights- poor performance. I thought I’d be marked down as a serial complainer!

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Reviewed 7th November 2018 by Janet

The seedlings arrived in May, so not so recent. I planted them in same area. Half the plants flowered well throughout the summer. The others grew plenty of foliage but only flowers in late September!
Exactly the same soil and position. I wasn’t aware they were different varieties.

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Reviewed 7th November 2018 by Mr Sampson

Good service, loads of flowers, plants did get a bit leggy towards the end so need staking

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Reviewed 31st October 2018 by Hilary

Poor results. Grown in pots, few flowers.

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Reviewed 11th October 2018 by Sue

Rather weak compared to the white ones.

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Reviewed 11th October 2018 by Colleen

Flowered profusely and did not grow too tall.

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Reviewed 3rd October 2018 by Anita

A very good show and some are still in flower. Some of the seedlings did not flower although plants grew tall and feathery.

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Reviewed 19th September 2018 by Linda

The service was exxcellent, the plants in good condition and they are still flowering, about 4ft tall, excellent

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Reviewed 19th September 2018 by Maureen

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Reviewed 19th September 2018 by Gillian

Very efficient and arrived in a good condition

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Reviewed 17th September 2018 by Joanna

I thought the cosmos were too tall and Leggy and I had to stake them all

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Reviewed 13th September 2018 by Lynda

They have grown very well, but I would have liked them to be a darker mix. They don't exactly match the flowers around them

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Reviewed 5th September 2018 by Sheena

plants came in excellent condition. They are still blooming now - beginning of September

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Reviewed 5th September 2018 by Yvonne

Strong healthy plants and the colour is great for my garden

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Reviewed 4th September 2018 by Susan

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Reviewed 3rd September 2018 by Jill

Excellent service.
Grew well in spite of exceptional weather conditions.

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Reviewed 2nd September 2018 by Susan

Cosmos seedlings arrived in great condition, the plants have flowered for weeks, still look good and are a lovely deep colour.very pleased with them

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Reviewed 2nd September 2018 by Ann

The seedlings were very small and weak when they arrived.I nurtured them under cover but finally they resulted in only 4 bushes bearing blooms - 2 pink 2 red These have bloomed prolifically although halfway through the summer season, one red plant almost died on me ( not because of lack of watering) but after pruning it,rallied and has developed into a smaller bush. I was disappointed as I had anticipated having many more mature flowering plants to make a colourful show in a large flower bed

Reply from the Sarah Raven Team:

"Thank you for leaving your review. We are very sorry to hear of your disappointment with your cosmos seedlings and have refunded you for them."

Posted 7th November 2018

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Reviewed 29th August 2018 by Mr Birchard

Dear Sarah,

You send out far too many emails. While I very much admire your work, I find that so many emails puts me off and makes me not want to look. I am sure this is not what is intended.

Thaddeus Birchard

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Reviewed 29th August 2018 by Wendy

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Reviewed 29th August 2018 by Ms Middleditch

The cosmos last all through the summer and give the garden wonderful colour.

Dark cosmos collection

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Reviewed 18th April 2015 by Fiona jacovides

Disappointed with my seedlings. Some of them looked Very spindly. It remains to be seen how well they will do. I wouldn't have picked these if I had gone to the garden centre I would have gone for healthier looking plants.

Reply from the Sarah Raven Team:

"Hi Fiona, Thank you for your review. We are so sorry to hear that this has happened, but it sounds like they may have been wrapped a bit prematurely and then delayed in the post, causing them to look this way. Please get in contact at info@sarahraven.com or give us a call and we will more than happily arrange for replacement plants to be sent to you."

Posted 23rd April 2015

some seedlings poor quality

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Reviewed 18th April 2015 by Hilary Walton

Had to re-order the Cosmos Antiquity as they arrived in poor condition, quite different from the other two in the collection. The new seedlings have yet to arrive. Am sure they will all give a good show later on!

Reply from the Sarah Raven Team:

"Hi Hilary, we are so sorry to hear that they've arrived this way. We are aware that the Antiquity did not grow on as quickly as the other two varieties, however we are confident that you should have a good display later in the season. If you have any problems with the new ones that are on their way, please do contact us on the phone or via email at info@sarahraven.com and we will do our best to help."

Posted 23rd April 2015

Wonderful long-lasting show

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Reviewed 22nd November 2014 by Red Squirrel

I bought this dark cosmos mix along with the pale cosmos collection and mixed the seeds together. They were planted in a long border along with tall salvias and they have been a wonderful show of colour since mid July and are only now (mid Nov) starting to look shabby. You must continually deadhead though to keep them flowering. I have picked many bunches of them and they look so nice in a pretty little vase.

Still Flowering in October

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Reviewed 16th June 2014 by Brown Owl

Got this set of 15 in June after my own seeds failed to germinate because it was such a cold spring. I'm glad I did as by August I had a wonderful display of cosmos no doubt helped by such a heatwave. With half term coming up l still have lots of cosmos on display its underplanted with some orange Scura dahlias and looks stunning. The Dazzler is my favourite of the three tall, floriforous and bright pink.